Process for producing 2-mercapto-arylene-thiazole compounds and the products



Patented Sept. 13, 1932 UNITED. STAT S RICHARD HERZ, or rnnnxronr-o -rrrn-mnm, ND MAX sonursnar, on FRANKFOBT:

oN-rHE-MArN-rEoHENHEIM,

rNo., on NEW YORK N. 2., A coRronA'rro or DELAWARE I rnocnss FOR rnonUcrNe z-mnncnrro-AnYnnNn-rnrAzoLn COMPOUNDS AND THE I rnonuc'rs '1 GERMANY, AssrGNons T0 GENERAL; ANIIQILTE worms,

No Drawing. Application filed February 15, 1929, Serialglflo. 340,827, and in Germany February 24, T1928 Our present invention relates to a process for producing 2-mercapto-arylene-thiazoles of the probable general formula:

s i p wherein R means an arylene residue whichmay contain further substituents, such as,for instance, halogen, alkyl'-, alkoxyaminoor arylamino-groups.

This process consists inacting with a thiocarbonic acid compound of the general formula:

wherein X means -()-alkali metal, -S- alkali metal or -O-alkyl,either' in'situ or in substance in the presenceof an alkali and advantageously with the addition of a reducing agent on an 'ortho-amino-aryl-sulfo-cyanogen compound of the general formula wherein arylene means a residue, of the above-mentioned kind (see U. S. Patent No. 1,765,678).

As alkali sulfides act simultaneously as alkaliland asreducing agents, further addition of alkali or of a reducing'agentis not necessary'in this case.. 1 E v In order to apply the thiocarbonic acid compounds in situ, for instance, a trithiocarbonate may be substituted by carbon disulfide and alkali sulfide or a di-thio-carbonate by carbon disulfide and an alkali or a xanthogenate by carbon .disulfide, alkali and alcohol; 1 a p I It is a remarkable fact that the reaction is finished after a short tinie, in most cases already by warming the starting materials for some hours, and that completely pure products are obtained with an excellent yield in a smooth reaction. t p v 7 The Q-mercapto-arylene-thiazoles, thus obtained, are identical with thoseobtained according to the process described in the U. SQ

Patent No. 1,847,514.

In order to further illustrate our invention, the following examples are given, the parts being by weight and all temperatures incentigrade degrees. 1 We wish it however to be understood that'we-are not limited to the particular products nor reaction conditions mentioned therein.

Ewample l 90 parts of l-methyl-Q-amirro-3-sulfocyanogen-5-chloro-benzene are boiledin a solu- 7 tion of 160 parts of crystallized sodium sul fide in 1600 parts of water and 20 parts of carbon disulfide under .a. reflux condenser for several hours, 10 parts of carbon disulfide being advantageously added after some time, When cool the reaction mass is acidulated' and the precipitate formed is filtered on; His purified by, dissolving itina warm aqueous ammonia'solution and precipitated therefrom by means of hydrochloric acid. 7 The Q-mercapto-fl-methyl-G- chloro-benzothiazole corresponds probably tothe. formula:

I i CH:

benzene, colorless needles melting at 252?. is identical with the product described in" Example 2-of U. SQPaten't No.1,847,5 14. I v. V I nmet u v EwampZe,@" "[42 1 parts, of; naphthalene are 7 1-sulfocyanogen-2amino{ boiled incasolution of 160' partsof crystallized sodium sulfidein 800- and represents, when recrystallized; from H described by J akobsen and Frankenbacher (Berichte der deutschen chemischen Gesellschaft Vol. 24, page 1408).

Ewample3 v 45 parts of 2-amino-3-sulfocyanogen-1.5-

dimethyl-benzene and parts of sodium hy-r. drosulfite are dissolved in the hot in 300 parts of alcohol and 75 parts of a caustic soda solution of strength and the solution is boiled with the addition of 300 parts of water and 25 parts of carbon disulfide under a reflux condenser for about 1 hour. Then the alcohol is distilled off, the residue is digested with water, the undissolved part is filteredoff and the filtrate thereof is acidulated. The precipitated reaction product is purified by dissolving it in a cold dilute caustic soda solution and the solution is-preeipitated with an -acid. The Q-mercapto-tfi-dimethyl benzothiazole of the probable formula:

WVhen 2-amino-3-sulfocyanogen 1.5 di- "methyl-benzene is replaced by the same quantity of 4-amino-3-su1focyanogen-1-methylbenzene and the process is carried out otherwise in the same way, 2-mercapto-6-methylbenzo-thiazole is obtained.

Emample 4 When amino-disulfocyanogen compounds containing one sulfocyanogen group in the ortho-position relating to the amino-group are treated in the manner described in exam ple 3, the other sulfo-cyanogen group is converted into a mercaptan or a disulfide residue besides the formation of the thiazole ring.

E. g. 36 parts of 2.4;-disulfocyanogen-aniline, described in example 4 of the French Patent No. 620,799 dated August 26, 1926, are boiled with a solution of 160 parts of sodium sulfide in 800 parts of water and 15 parts of carbon-disulfide under a reflux condenser for several hours. The clear solution is acidified when cool and the precipitated reaction prodnot is filtered oft For purification it is dissolved in a cold dilute caustic soda solution with the addition of some hydrosulfite and precipitated from this solution with a dilute acid. The new compond, thus obtained, be

ing probably 2.6-dimercaptobenzothiazole of the formula:

crystallized from dilute acetone in colorless needles melting at 275.

.methoxy-Q-mercapto-benzo-thiazole of about 2059v melting point. By, starting from 1.3- dimethyl-4- chloro 6 amino 5 sulfocyanogenobenzene and 1.3-dimethyl-EZAL-dichloro-6- amino-5-sulfocyanogeno benzene according ly, 4.6-dimethyl-7-chloro-2-mercapto-benzothiazole of about 305 melting point and 4.6- dim'etl1yl-I 5.7 -dichloro-2rmercaptosbenzothiazole respectively of about 290 melting point are obtained. All these compounds are new.

We claim: 1. A process which comprises acting with a thiocarbonic acid compound of the general formula: V

S ---alkali metal s o I wherein X means O-alkali metal, -S-alkali metalor -O.-alkyl, in presence of an alkali on an otho-aminoaryl-sulfocyanogen compound of the general formula:

NH 1 R 2 SON 2 wherein R means naphthalene or a radical of the benzene serles whlch may contain chlorine, methyl or vinethoxy.

2. A process wh chcomprises acting with a thlocarbonlc acid compound of the general formula:

wherein X means O-alkalimetal, -S-alkali wherein X means O-alkali metal, -S-alkali metalor -,O-alkyl produced in situ presence of an alkali: on an ortho-aminoaryl-sulfd cyanogen compound of the general formula:

NH5 1 soN (a wherein R meansnaphthalene or a radical of the benzene s'eries which may contain chlorine methyl or methoxy.

4. A process which comprisesacting with a thiocarbonic acid compound of the general formula:

S-alka1i metal wherein X means -O-alkali metal-, -S-alkali metalor O-alkyl produced in situ, in presence of an alkaline reducing agent on an ortho-aminoaryl-sulfocyanogen compound of the general formula:

NH: 1 SON 2 NH: (1) R SCN (2) wherein R means naphthalene or a radical of the benzene series which may contain chlorine, methyl or methoxy.

6. A process which comprises acting with an alkali-sulfide and carbon-disulfide on an ortho-aminoaryl-sulfocyanogen compound of the general formula:

SON (2) wherein R- means naphthalene or a radical of the benzene series which may contain chlorine, methyl or methoxy.

7. As new compounds the chlorinated 4.6- dimethyl-2-1nercapto-benzothiazoles corresponding to the general formula:

wherein X stands for hydrogen or chlorine, which compounds melt between about 290 and 305 C.

In testimony whereof, we afiix our signatures.

RICHARD HERZ. MAX SCHUBERT. 

